Charles e



Patented June 3,1890.

ms TE" 20., mmo-ur UNITED STATES PATENT OEEIcE.

CHARLES E. CARPENTER, OF MINNEAPOLIS, MINNESOTA, ASSIGNOR, BY DI- RECT AND MESNE ASSIGNMENTS, TO THE CARPENTER-NEVENS ELEC- TRO-HEATING COMPANY, OF SAME PLACE.

ELECTRIC-HEATING APPARATUS.

SPECIFICATION forming part of Letters Patent No. 429,560, dated June 3, 1890.

Application filed December 17, 1889. Serial No. 384,126. (No model.)

To all whom it may concern: 2; Fig. 4, a diagram view illustrating the ar- Be it known that I, CHARLES E. CARPEN- rangement and distribution of the conductor TER,a citizen of the United States, and a resi constituting the resistance for the electric dent of the city of Minneapolis, in the county current and the connection thereof with the 5 of Hennepin and State of Minnesota, have source of power.

invented certain new and useful Improve- This invention, so far as relates to the charments in Electro-Heating Apparatus, of which acter, form, and relation of the elements, and

the following is a full, clear, and exact dethe manner of economicallyutilizing the heat scription. evolved by the resistance is similar to the ap- 10 This invention relates to improvements in paratus shown in Letters Patent of the electro-heating apparatus for utilizing the United States, N 0. 415,856, granted me Noheat developed by passing a current of elecvember 26, 1889, and allowed September 14, tricity through a conductor of high resistance 1889, the main point of difference being that and small capacity for the purposes of an atthe object of that invention, generally stated,

I5 mospheric heater, and differs from other apwas to direct and confine the heat generated paratus heretofore invented by myself and to the surface-plate of the apparatus or utenothers, in which the principal feature was the sil to which the invention was applied, and confining of the heat developed to a single at the same time prevent the dissipation of surface of the apparatus. the heat by conduction or radiation to other 20 The prime object of this invention, there bodies; but this invention has exactly the op fore, is to have the heating apparatus of such posite purpose in viewnamely, to dissipate a character that the heat generated thereby the heat into the atmosphere in all directions will be dissipated into the atmosphere by and as rapidly as possible, in order that the 7 5 radiation, conduction, or convection with the invention may be applied to all the purposes 2 5 maximum degree of rapidity, whereby great of an atmospheric heater of convenient form,

economy in electrical heating is effected and and as simple in construction as the apparaat the minimum expense. tus heretofore invented.

Other objects of this invention are to se- Referring now to the drawings, let A rep- 8o cure the maximum radiations in all directions resent a sheet or card of asbestus, of suitable 0 from the apparatus; to have the apparatus thickness, or of any other incombustible elecconvenient and durable in form and of light trical insulating material,to one or both faces weight and economicalconstruction; to avoid of which is secured, by means of asbestus the reaction of the heat upon the resistance thread, staples, or other form of fastening, an and thus avoid danger of fusion or oxidation electrical conductor or resistance B, prefera- 3 5 of the resistance; to subject the resistance to bly consisting of wire of high resistance and a constant pressure, whereby the heating efsmall capacity, preferably reflexed back and fects thereof are not only intensified, but the forth over the faces of the asbestus card in deterioration thereof isprevented,and,finally, substantially the manner illustrated in Fig. 0 to provide certain details in the carrying out 4, with one terminal C of each resistance con- 0 of my invention, all as illustrated in the acnecting with one of the line-wires D from the companying drawings, in which source of electrical energy and the other ter- Figure 1 represents a perspective view of minals E with the other line-wire F, there one form of electro-heating apparatus embeing included in one of these terminals bebodying my invention; Fig. 2, a perspective tween the resistance and line-wire'a switch 45 view of another form of heating apparatus G, of some suitable form, for making and embodying my invention; Fig. 3, a horizontal breaking the circuit through the resistance, section through the heater shown in Fig. 1, so as to control the heating thereof. Against illustrating the relation of the elements thereeach of these resistances is laid a sheet H, of of, and which also represents asection taken some electrical insulating materialsuch as 50 at any point through Fig. 2, with the eXcepthin asbestus paper, mica, or the 1ikewhich, tion of the bolts intermediate the ends, which while they permit the comparatively free pasare not shown, but might be employed in Fig. sage through them by conduction of the heat evolved by the resistances, at the same time serve to electrically insulate the resistances from the exterior surface-plates I on each face of the apparatus, which also serve as a means for binding all the elements firmlytogether in a compactbody and under a proper degree of pressure by means of screws J, preferably passing through all of the elements and having ornamental nuts K upon their opposite ends corresponding with the heads of the screws upon the other side of the apparatus. If desired, for further ornament and finish, a binding strap or band L of metal may be secured to the edges of the elements by the outer line of screws, so as to present a finished appearance and furnish a surface capable of any desired degree of ornamentation.

The heating surface-plates I are preferably made of Russia iron, so as to offer as little resistance as possible to the escape of the heat evolved by the resistances and transmitted thereto through the medium of the electrical insulators H, which should be of such a character that they will endure high temperature and be fairly good conductors of heat. For this reason I prefer to use a thin compact asbestus paper as the electrical insulating material, for while mica, and even some forms of insulating-paint which is fireproof or will endure high temperature, may be employed for this purpose, still, by reason of their rigid unyielding character, they present only a small surface for contact with a wire by reason of the meeting of their plane with the curved surface of the wire, thus reducing their utility as conductors for the heat evolved by the resistance. Asbestus paper or some other flexible and yielding material, on the contrary, will permit the sinking of the wires into the surface thereof under pressure, so that the insulator will press closely around nearly half of the circumference of the wire, and thus furnish the maximum degree of contacting-surface.

Practice has demonstrated that with the structure above described, and illustrated in the drawings, oxidized wires of German silver if subjected to considerable pressure in the relation described by bolting the heatingsurfaces together, as shown, or in any other well-known and convenient manner, do not decompose or deteriorate when subjected to high temperature, such as would result from passing heavy currents through them, and are thereby rendered practically indestructible.

Another advantage of this construction of electro -heating apparatus is that a large amount of heating-surface is obtained for a small bulk and weight of material, and that the same wires which would become fused or deteriorate with use when subjected to heavy currents if placed in any convenient form for usesuch as a coil not under pressureor in any other shape exposed to the atmosphere, do not deteriorate when used in the construction and relation shown.

\Vith this structure of the apparatus various modifications of its appearance and form maybe made to suit any requirement. For example, as illustrated in Fig. 1, it may be flat with straight or plane sides,or, as illustrated in Fig. circular or cylindrical in form, with one of the heating surface-plates on the inside of the cylinder and the other outside of the cylinder. Furthermore, theheated surface-plates may have a plain exterior or may be ornamented in any desirable manner and provided with ornamental studded points, some of which may, if desired, be the heads and nuts for the screws; or the surface may be corrugated, angular, or have any other desirable configuration.

llaving described my invention, what I claim, and desire to secure by Letters Patent, is

1. In an electro -heating apparatus, the combination, with an internal layer or card of iucombustible electrical insulating material and resistances lying on one or both faces thereof, of a layer of electrical insulating material covering each of saidresistances and exterior heating surface-plates, substantially as and for the purpose described.

In an clcctro-heating apparatus, the

combination, with the internal layer or card 9 of in combustible electricalinsulatin g material and resistances lying against one or both faces thereof, of a layer of electrical insulating material covering each of said resistances, exterior heated surface-plates between which said elements are confined, and screws or other equivalents for binding all the elements together and maintaining them under pressure, substantially as described.

3. In an electro-heating apparatus, the combination, with an internal layer of incombustible electrical insulating material and resistances consisting of reilexed wire secured to each face thereof, of a layer of; electrical insulating material covering each of said resistances, external heated surfaceplates covering each of said insulators, and screws passing through said surface-plates, and the intermediate elements detachably securing all of said elements together under pressure, substantially as described.

CHARLES E. CARPENTER.

Witnesses:

M. F. SooFinLn, RoBT. T. LANG. 

